Probing macrophage cell nucleotide sensing and calcium signaling through computation

而在fl，羊膜是一种自然的免疫系统反应，开始了愈合过程，而在flAm，则是慢性的。 信息与许多人类疾病有关，包括癌症、心脏功能障碍和败血症。的一个关键要素 在fl中，炎症反应是巨噬细胞，一种清除病原体或死亡组织的白细胞。一个 内源性危险信号三磷酸腺苷在fl炎症通路中刺激钙依赖 巨噬细胞。虽然之前的研究在理解fl氨基酸方面取得了很大进展，但我的实验室试图 通过多尺度计算模型揭示三磷酸腺苷在fl炎症反应中驱动巨噬细胞的作用 我们发展。利用巨噬细胞内fl炎症反应的新模型，我们的实验室可以预测蛋白质和细胞 在集成的生理系统中的行为，以更好地了解免疫系统。 目前在巨噬细胞中由三磷酸腺苷触发的fl氨化的范例是核苷酸- 感知P2X通道在fl炎症反应中的敏感性，包括细胞因子和活性氧(ROS) 放手。然而，这种范式并不能解释几个观察结果。一个，而P2X表达是 在fl炎性巨噬细胞中，这些受体也支持静息时的吞噬和迁移 巨噬细胞。这些过程是如何被像P2X4和P2X7这样的P2X亚型选择性控制的还没有解决。 第二，在fl炎症巨噬细胞中，含有许多感受钙的蛋白质的翻译后Modifi阳离子(PTM)， 然而，人们对PTM如何影响它们控制的免疫途径知之甚少。三、三磷酸腺苷的释放和降解 通过膜联蛋白和胞外核苷酸酶控制激活P2X的ATP，但很少有研究评估它们的偶联作用。 我们的实验室处于独特的位置，可以通过探测这些观察的基础机制来扩展这一范式 在fl氨化过程中，P2X-、ATP3-和Ca-的偶联作用在很大程度上尚未被研究。我们的实验室和组装的合作实验室- 演说者将通过计算建模和实验方法研究整个假说：P2X 巨噬细胞中的通道通过三磷酸腺苷诱导的fl释放(自分泌)帮助慢性三磷酸腺苷的形成 选择性启动钙依赖的、支持fl的炎性信号通路的机制。这一假设 源于我们在最初的ESI Mira奖期间的调查中出现的问题：1.是否增加了 巨噬细胞中P2X4和P2X7的表达及其诱导的钙信号延长fl前炎症反应 细胞因子和ROS的释放？2.钙传感器钙调素(CaM)中类似ROS氧化的PTM是否减弱其 fl前体炎症信号通路的激活--3.DO(自分泌)诱导巨噬细胞释放 延长fl前体细胞内钙的炎性增加？ 我们通过计算了解巨噬细胞生理学的长期目标将会加快。 被提议的调查所影响。这一赠款期间的主要预期成果包括新机制和 模拟工具，自分泌，三磷酸腺苷驱动的fl炎症反应介导性的P2X受体。因为所有的 真核细胞使用钙，对巨噬细胞建模的洞察将产生免疫功能以外的广泛影响。

While inflammation is a natural immune system response that begins the healing process, chronic inflam- mation is tied to many human diseases including cancer, cardiac dysfunction, and sepsis. A key element of inflammatory responses are macrophages, a white blood cell that eliminates pathogens or dying tissues. An endogenous 'danger signal', adenosine triphosphate (ATP), stimulates Ca-dependent inflammatory pathways in macrophages. While previous research has made great strides in understanding inflammation, my lab seeks to uncover roles of ATP in driving macrophage inflammatory responses through multi-scale computational models we develop. With new models of inflammatory responses in macrophages, our lab can predict protein and cell behavior in integrated, physiological systems to better understand the immune system. The current paradigm for ATP-triggered inflammation in macrophages is that upregulation of nucleotide- sensing P2X channels sensitizes inflammatory responses, including cytokine and reactive oxygen species (ROS) release. However, this paradigm does not account for several observations. One, while P2X expression is increased in inflammatory macrophages, these receptors also support phagocytosis and migration in resting macrophages. How these processes are selectively controlled by P2X subtypes like P2X4 and P2X7 is unresolved. Two, inflammatory macrophages harbor post-translational modifications (PTMs) of many proteins that sense Ca, yet little is known about how PTMs impact immune pathways they control. Three, release and degradation of ATP by pannexins and ectonucleotidases control ATP that activates P2X, yet few studies have evaluated their coupling. Our lab is uniquely positioned to extend this paradigm by probing mechanisms underlying these observations and the largely unstudied coupling of P2X-, ATP-, and Ca-driven inflammation. Our lab and assembled collab- orators will investigate the overall hypothesis via computational modeling and experimental approaches: P2X channels in macrophages help nucleate chronic inflammation via ATP-induced ATP release (autocrinic) mechanisms that selectively prime Ca-dependent, pro-inflammatory signaling pathways. This hypothesis stems from questions that emerged from our investigations during the initial ESI MIRA award: 1. Does increased P2X4 and P2X7 expression and the resulting Ca signals they induce in macrophages prolong pro-inflammatory release of cytokines and ROS? 2. Do PTMs like ROS oxidation in the Ca-sensor calmodulin (CaM) attenuate its activation of pro-inflammatory signaling pathways? 3. Do (autocrinic) ATP-induced, ATP release in macrophages prolong pro-inflammatory increases in intracellular Ca? Our long-term goal to understand macrophage physiology through computation will be accelerated by the proposed investigations. Key expected outcomes from this grant period include new mechanisms and simulation tools for autocrinic, ATP-driven inflammatory responses mediated by P2X receptors. Since all Eukaryotic cells use Ca, insights from modeling macrophages will have broad impacts beyond immune function.